Abstract

Aim

Obinutuzumab, also known as GA101 (G), is a novel therapy shown to have improved progression-free survival in combination with chlorambucil (GClb) compared to rituximab + chlorambucil (RClb) in the recent CLL-11 trial for previously untreated CLL. We set out to evaluate the incremental cost-effectiveness of G vs. rituximab(R).

Methods

Patient outcomes were simulated using a 3-state Markov model that included PFS, progression, and death. The patient population was assumed to be analogous to that studied in the CLL-11 trial. Efficacy parameters were 1) probability of progression, and 2) probability of dying after disease progression. The model parameters were fitted to the observed trial data. Drug utilization and adverse events were incorporated based on trial data, and costs were based on Medicare reimbursements and drug wholesale acquisition costs. Sensitivity analyses were conducted to assess uncertainty in the results.

Results

Treatment with GClb led to an increase in average life years (+0.62 y) and quality-adjusted life years (QALYs)(+0.55 y) relative to RClb, respectively. The average total costs were similar, with higher drug and adverse event costs for GClb being offset by higher cost of disease progression with RClb.

Outcome

GClb

RClb

Difference

Average life years

5.48

4.85

0.62

Average QALYs

3.71

3.15

0.55

Total Drug Costs

&dollar;37,313

&dollar;34,714

&dollar;2,599

Drug Administration

&dollar;1,974

&dollar;1,455

&dollar;522

Supportive Care

&dollar;128

&dollar;75

&dollar;53

Adverse Events

&dollar;9,524

&dollar;6,766

&dollar;2,758

Cost of Progression

&dollar;46,608

&dollar;52,476

-&dollar;5,868

Average Total Costs

&dollar;95,550

&dollar;95,486

&dollar;64

In probabilistic sensitivity analyses, the difference in QALYs ranged from 0.36 to 0.79, and the difference in total cost ranged from approximately -&dollar;69,000 to &dollar;58,000.

Conclusions

Based on the results of the CLL-11 trial, our analysis suggests treatment with GClb compared to RClb is likely cost-effective with improved outcomes and comparable costs. Further analyses based on indirect comparisons with other treatment options, as well as updated follow-up data, will help inform coverage and reimbursement policy decisions.

Disclosure

C. Reyes: Employee of Genentech Inc, Roche Stocks. All other authors have declared no conflicts of interest.